Characterization of a Canine Model of Autosomal Recessive Retinitis Pigmentosa due to a PDE6A Mutation
Characterization of a Canine Model of Autosomal Recessive Retinitis Pigmentosa due to a PDE6A Mutation
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DOI：
10.1167/iovs.08-2562
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发表时间：
2009-02-01
影响因子：
4.4
通讯作者：
Petersen-Jones, Simon M.
中科院分区：
文献类型：
--
作者：
Tuntivanich, Nalinee;Pittler, Steven J.;Petersen-Jones, Simon M.
目的.描述一种由PDE 6A基因突变引起的常染色体隐性遗传RP犬模型。通过视网膜电图（ERG）、光学和电子显微镜、免疫组织化学和视网膜PDE 6水平和酶活性测定，研究了受影响的和品种和年龄匹配的对照幼犬。突变的幼犬未能发展正常的视杆细胞介导的ERG反应，并且从早期开始就具有降低的光适应a波振幅。残留的ERG波形主要来源于视锥细胞驱动的反应。光感受器外节的发育停止，视杆细胞因凋亡而丢失。免疫组化显示，在疾病过程的早期，视杆细胞视蛋白免疫染色的外节和视锥细胞的相对保存显着减少。除了视杆双极细胞，这似乎是减少的数量相对较早的疾病过程中，其他内部的视网膜细胞被保存在疾病的早期阶段，虽然有显着和早期激活的穆勒胶质细胞。Western blot分析表明，PDE 6A突变不仅导致PDE 6A蛋白的缺乏，而且受影响的视网膜也缺乏其他PDE 6亚基，这表明PDE 6A的表达是PDE 6 B和PDE 6 G正常表达所必需的。受影响的视网膜缺乏PDE 6酶活性。这代表了常染色体隐性视网膜色素变性的PDE 6A模型的第一个表征，并且PDE 6A突变狗显示出作为研究治疗以拯救突变视杆光感受器和在视杆细胞快速损失的情况下保护视锥光感受器的大型动物模型的希望。（Invest Ophthalmol维斯科学。2009;50：801-813）DOI：10.1167/iovs.08-2562
PURPOSE. To characterize a canine model of autosomal recessive RP due to a PDE6A gene mutation.METHODS. Affected and breed- and age-matched control puppies were studied by electroretinography (ERG), light and electron microscopy, immunohistochemistry, and assay for retinal PDE6 levels and enzymatic activity.RESULTS. The mutant puppies failed to develop normal rod-mediated ERG responses and had reduced light-adapted a-wave amplitudes from an early age. The residual ERG waveforms originated primarily from cone-driven responses. Development of photoreceptor outer segments stopped, and rod cells were lost by apoptosis. Immunohistochemistry demonstrated a marked reduction in rod opsin immunostaining outer segments and relative preservation of cones early in the disease process. With exception of rod bipolar cells, which appeared to be reduced in number relatively early in the disease process, other inner retinal cells were preserved in the early stages of the disease, although there was marked and early activation of Muller glia. Western blot analysis showed that the PDE6A mutation not only resulted in a lack of PDE6A protein but the affected retinas also lacked the other PDE6 subunits, suggesting expression of PDE6A is essential for normal expression of PDE6B and PDE6G. Affected retinas lacked PDE6 enzymatic activity.CONCLUSIONS. This represents the first characterization of a PDE6A model of autosomal recessive retinitis pigmentosa, and the PDE6A mutant dog shows promise as a large animal model for investigation of therapies to rescue mutant rod photoreceptors and to preserve cone photoreceptors in the face of a rapid loss of rod cells. (Invest Ophthalmol Vis Sci. 2009;50:801-813) DOI:10.1167/iovs.08-2562